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Earthquake Research in China
Volume 26，Number 2，2012
Field Geological Exploration of the
Ashikule Volcano Group in
Western Kunlun Mountains1
Xu Jiandong 1 ) ，Zhao Bo 1 ) ，Zhang Liuyi 1) ，and Chen Zhengquan 2)
1 ) Key Laboratory of Active Tectonics and Volcano，Institute of Geology，CEA，Beijing 100029 ，China
2 ) College of Resource Environment and Tourism，Capital Normal University，Beijing 100048 ，China
From May 4 to May 30，2011，a field exploration of the Ashikule basin in the Western
Kunlun Mountains area was conducted by a research team from the Institute of Geology，
China Earthquake Administration and Earthquake Administration of Xinjiang Uygur
Autonomous Region． This work is financially supported by the special fund for China
earthquake research project “The Comprehensive Scientific Exploration of the M S 7. 3
Yutian Earthquake in 2008 and the Ashikule Volcano Group ”． Through detailed field
survey on geological and geomorphological features of the Ashikule volcano group，which
is one of the highest altitude volcanic plateaus ( about 5000m ) in the world，we have
determined the total number of volcanoes，the eruption type and structural parameters，
and approximate active history of the volcano group． Our studies have provided field
evidence for resolving past controversies such as the authenticity of the news report about
the eruption event on May 27，1951，the eruption pattern of the Daheishan volcano，and
the reality of the Gaotaishan volcano．
Key words: Ashikule volcano group; Recent eruption; Volcano cone; Lava
INTRODUCTION
Ashikule basin is located at the junction of Altyn fault，on western segment of the eastern
Kunlun fault，and Kangxiwa fault ( Fig． 1a ) ． As a tectonic basin predominated by extensional
stress conditions accompanied by shearing，Ashikule basin has undergone intensively neo-tectonic
processes due to its special tectonic background． The Ashikule volcano group，which is composed
of 10 major volcanoes and tens of sub-volcanoes，covers a total area of about 200km 2 at the
average altitude around 5000m，one of the highest volcano groups in the world ( Fig． 1b ) ． The
1
Received on August 21，2011; revised on September 13，2011． This project is sponsored by the Special Fund
for China Earthquake Research (201008004) and the Special Projects of the Fundamental Scientific Research of
the Institute of Geology，CEA ( IGCEA1101) ．
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153
most volcanoes in the basin formed and developed in the Quaternary period in central vent
eruption mode ( Deng Wanming，1989; Liu Jiaqi et al． ，1990 ) ，so the craters are shaped as
typical cones or truncated cones． An explosive eruption was reported to have occurred in the basin
on May 27，1951 by Xinjiang Newspaper，which has been believed to be the most recent volcanic
eruption event in the Qinghai-Tibetan plateau ( Xinjiang Daily，1951 ) ． However，the reality of
such an event has been debated for several decades since no solid evidence，associated with
eruptions such as lava，has been found in the field ( Deng Wanming，1989;Li Shuanke，1991;
Liu Jiaqi et al． ，1990;Liu Ruoxin et al． ，2000) ． Some reconnaissance field work was carried out
to conduct an in situ investigation on the volcano field in the basin in the late 1980's by QinghaiTibetan research team members from the Chinese Academy of Sciences． Afterwards，more field
work and geological mapping of the Cenozoic volcanic rock in the Ashikule basin was done by the
Chinese Academy of Geological Sciences in 2008，when the earthquake emergency expedition was
organized to investigate the surface rupture produced by the Yutian M S 7. 3 earthquake occurring
south of Ashikule basin on March 20，2008． However，such an uninhabited area with a high
altitude，where the Ashikule volcano group is situated，made the basin almost inaccessible for
volcanologists to conduct detailed field work in the past． Indeed，the limited previous work only
provides some basic understanding of volcanic petrology，geochemistry and brief chronology of
volcanism． Some fundamental questions regarding the deep source of magma ( where ?) ，
evolution process ( how ?) and current state of magma chamber ( what ?) are still kept open．
In this paper，we report the most up-to-date results from a one-month field expedition in the
Ashikule basin． This work was conducted by the special research team from the Institute of
Geology，China Earthquake Administration and Earthquake Administration of Xinjiang Uygur
Autonomous Region，which is financially supported by the special fund for the China earthquake
research project “The Comprehensive Scientific Exploration of Yutian M S 7. 3 Earthquake in 2008
and Ashikule Volcano Group”．
1 GEOLOGICAL AND GEOMORPHOLOGICAL FEATURES OF THE ASHIKULE
VOLCANO GROUP
The Ashikule volcano group consists of a volcanic series from the late Pliocene epoch (2. 8
Ma) to the Holocene， which was classified into 6 volcanic episodes based on the field
investigation and K-Ar dating of volcanic rock samples in the previous work ( Liu Jiaqi et al． ，
1990) ． Some evidence presented by Liu Jiaqi et al． in 1990 supports the possibility of the most
recent eruption on May 27，1951 that was originally reported by Xinjiang Daily ( 1951 ) ． The
typical geomorphological features of the volcano group include volcanic cones，lava terraces and
lava valleys． Several volcanic chains and clusters in the NE direction are well developed that may
be attributed to the regional NE-trending tectonic activity during the eruptions． The main volcanic
series of the Ashikule group is lithologically characterized by trachyandesite，trachybasalt and
tephrite ( Liu Jiaqi，1999) ．
1. 1
Ashishan Volcano
This volcano，also referred as volcano #1 in the previous work ( Zhao Mingyu，1976 ) ，lies
on the south of Ashikule basin ( Figs． 1b，2a) ． Liu Jiaqi et al． considered the Ashishan volcano
as the source of the most recent eruption event of 1951 ( Liu Jiaqi et al． ，1990 ) ． The well
preserved cone rises 110m above the basin． Inside the cone is an open space of 20m diameter at
base and 48m deep． The summit of the cone has a relative higher altitude at the north rim than in
south with a height difference of 26m． The outer surface of the cone is relatively smooth and no
obvious erosion ditches are observed． A couple of gas vents in diameter about 2m were found
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Fig． 1
The tectonic location of Arshikule basin ( a) and volcano distribution in the basin ( b)
Table 1
Geometric parameters of volcano cones and lava terraces of Ashikule volcano group
Volcano name
Diameter of cone
base / length of
terrace in the EW
direction ( m)
Diameter of cone
base / length of
terrace in the NS
direction ( m)
Diameter of cone
in the EW
direction ( m)
Diameter of cone
in the NS
direction ( m)
Ashishan
650
530
140
170
Daheishan
1100
1240
510
440
Wulukeshan
680
570
220
210
Yizishan
350
300
150
210
190
Migongshan
500
490
310
Yueyashan
230
210
90
70
Maoniushan
410
310
190
100
360
350
Matishan
580
530
Dongshan lava terrace
3130
3230
Xishan lava terrace
560
750
at the north rim of the cone ( Fig． 2b) that may be the result of the 1951 eruption． The whole
cone is covered with a very thin layer of loess due to the intensive loess activity in this region．
Ashishan lava has flowed in all directions from the crater，entering the Ashikule lake in the north
and stopped by the foot of the mountain in the south． In the broad distributed lava terrace，lava
lakes and splitting ridges can be seen． The structure of the Ashishan volcano cone shows at least
three stages during its formation． In the first stage the cinder cone was formed with the mixing of
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country rock debris，in black and dark brown color and relatively gentle outer slope． In the
second stage，dark brown-cascade deposits were formed around the crater rim by splashdown
accumulation，and the inner slope of the cone became steep． Finally，volcanic gas vents were
formed in the last stage．
1. 2
Daheishan Volcano
This volcano，also referred as volcano #2 in the previous work ( Zhao Mingyu，1976 ) ，is
located on the north of Ashikule basin ( Figs． 1b，2c) ． The previous K-Ar dating result suggests
that this volcano was formed around 0. 5 to 0. 6 Ma ( Liu Jiaqi et al． ，1990) ． As the largest and
highest volcano in the Ashikule basin，with the altitude of summit at 5090m，Daheishan volcano
has a broken cone with several pieces and barrancos on outer slope of the cone． Daheishan
volcano has history of multiple eruptions，in which the original cone was broken apart by the later
eruption that results in over 4 major pieces of the cone． Volcanic bombs with a diameter as large
as 1m can be seen at the north rim，and volcanic agglomerate is developed in the south flank．
This evidence indicates that an intensively explosive eruption once occurred． As the largest
volcano in the basin，the main flows from Daheishan have broad extent of blocky lava． They reach
the north mountain range，and run into and are covered by alluvia fans． Southward，the flows
reach the Ashikule lake． Overall， Daheishan volcano is characterized by both overflow and
explosive eruptions．
1. 3
W ulukeshan Volcano
This volcano，also referred as volcano #3 in the previous work ( Zhao Mingyu，1976 ) ，lies
800m northeast of the Wuluke lake ( Figs． 1b，2d ) ． The previous K-Ar dating result indicates
that this volcano was formed about 0. 2 Ma years ago ( Liu Jiaqi et al． ，1990 ) ． The cone of
Wuluke volcano is basically well preserved，and barrancos are developed at the outer slope． The
rim of the cone is sub-circular with a diameter of 220m． The north rim is about 30m higher than
the south． The structure of the Wulukeshan volcano cone reveals at least three stages during its
formation． In the early stage，the cinder cone was formed with the mixing of country rock debris，
black and red-brown colored with a relatively gentle outer slope． In the middle stage，red brown
splashdown accumulation was deposited around the rim． Unlike the Ashishan volcano，which has
a steep inner slope，the inner slope of Wuluke cone is quite gentle，which reflects the long-term
weathering process． In the last stage，ropy lava flowed towards the southwest，entering Wuluke
lake and north to encounter Ashishan lava．
1. 4
Yizishan Volcano
Yizishan volcano lies on a hillside west of the Wuluke lake ( Figs． 1b，2e) ． The previous KAr dating result indicates that this volcano was formed in about 0. 58Ma years ago ( Liu Jiaqi et
al． ，1990) ． “Yizi”means chair in Chinese，which indicates that the Yizishan cone is a “chairlike”shape with an outlet in NE direction． The inner crater rim is 150m long in the ES direction
and 210m long in the NS direction． A lava flow unit in a “tongue-shape ” can be clearly
recognized through the satellite image． Inside the rim，there are massive collapses，where lava
cakes and splashdown accumulation can be seen． The unique geomorphologic location of the
Yizishan volcano，which is quite different from that of most volcanoes in the basin，implies that
the development of the Yizishan volcano was controlled by the regional fault system．
1. 5
M igongshan Volcano
Migongshan volcano lies on a hillside 500m east of the Wulukeshan volcano ( Figs． 1b，2f) ．
The previous K-Ar dating result indicates that this volcano was formed about 0. 44Ma years ago
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Earthquake Research in China
Fig． 2
Some typical volcano cones and lava terraces of Ashikule volcano group
( a) Ashishan volcano ( view SW) ; ( b) Volcanic gas vent of Ashishan; ( c) Daheishan volcano ( view N) ;
( d) Wulude volcano ( view NW) ; ( e) Yizishan volcano ( view SW) ; ( f) Migongshan volcano ( view E) ;
( g) Yueyashan volcano ( view SW) ; ( h) Maoniushan volcano ( view S) ; ( i) Matishan volcano ( view N) ;
( j) Dongshan lava terrace; ( k) Xishan lava terrace; ( l) Cross-section along Maoniushan lava valley
( view SE) ; ( m) Volcanic chain in NE direction ( view N)
( Liu Jiaqi et al． ，1990) ． Like the Yizishan cone，Migongshan is also a “chair-like”cone with
an outlet about 130m wide． The “tongue-shaped”lava flows out from the break． Lava cakes are
well developed around the rim of the cone，and massive collapse materials can be seen in the
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inner rim． The major flow direction of the Migongshan lava is toward north，whereas the minor
flow is southwest．
1. 6
Yueyashan Volcano
Yueyashan volcano is located about 3km northeast of the Wuluke volcano ( Figs． 1b，2g) ．
Previous K-Ar dating indicates that this volcano was formed about 0. 31Ma years ago ( Liu Jiaqi et
al． ，1990) ． “Yueya”means half moon in Chinese，suggesting a “crescent-shaped”cone． The
rim of the Yueyashan cone is 70m × 90m． Due to strong weathering processes，the rim of the cone
flattens． Later lava，flowing out from the north break of the cone，is covered by the alluvial fans．
1. 7
M aoniushan Volcano
Maoniushan volcano is located about 720m northeast of the Yueyashan volcano ( Figs． 1b，
2h) ． The formation time of this volcano is unclear so far． The rim of the Yueyashan cone is 410m
× 310m in diameter． Due to strong weathering processes，the rim of the cone becomes butterflyshaped and flat． The lava originally flowed towards the north，then west after rounding the hill．
1. 8
M atishan Volcano
Matishan volcano is located on the northeast part of the Ashikule basin ( Figs． 1b，2i) ． The
previous K-Ar dating result indicates that this volcano was formed in about 1. 63Ma years ago ( Liu
Jiaqi et al． ，1990 ) ． Most part of this volcano is covered by alluvial fans，and the partially
exposed part appears in a “horse-shoe”shape，that is the meaning of “Mati”in Chinese． The
north rim is about 30m higher than the south． The whole exposed part of the cone is 10m to 30m
high above the alluvial fan． A parasitic volcano is found at the northeast slope of the cone． A
cross-section at the south slope of the cone reveals 3 layers from the bottom to the top，i． e． a 2m
thick red brown magma mass at the bottom; 1m thick volcanic cinder with abundant pores in the
middle; and red magma mass again at the top． Such a formation succession indicates the
explosive intensity changed from weak to strong，then from strong to weak again．
1. 9
Dongshan Lava Terrace
Dongshan lava terrace lies on the eastern part of the basin ( Figs． 1b，2j) ． No volcanic crater
was found in the field investigation． Instead，the undulated lava terrace with lava lobes and lava
valley is well developed． The previous K-Ar dating of lava shows a formation age of 0. 52 Ma
years ( Liu Jiaqi et al． ，1990 ) ． This lava terrace covers a total area of 6km 2 at an altitude
between 4640m to 4680m． The minimum thickness of the terrace is about 37m based on the field
survey． The surface of the terrace has been seriously weathered and dark porous lava particles in
a diameter of 1～ 5cm can be observed on the surface． The Dongshan lava terrace is the product of
the overflow eruption of the Dongshan volcano．
1. 10
Xishan Lava Terrace
Xishan lava terrace lies on the western part of the basin ( Figs． 1b，2k) ，18km away from
Daheishan volcano． The previous K-Ar dating of lava shows a formation age of 2. 8 Ma years，the
oldest volcanic rock in the basin ( Liu Jiaqi et al． ，1990 ) ． Like the Dongshan lava terrace，no
volcanic crater can be found． This lava terrace covers a total area of 0. 3km 2 at an altitude
between 4969m to 4996m，the highest lava terrace in the basin． The thickness of the terrace is
about 20m． On the surface of the terrace that has been seriously weathered，dark porous lava
particles in a diameter of 1～ 5cm with maximum of 5cm can be seen．
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1. 11
Binhu Volcanic Chain
Binhu volcanic chain，located at the southwest coast of Wuluke lake，consists of 6 round
hills in a northeast array ( Fig． 1b ) ． Among this chain，Gaotaishan is the largest one and is
located at the northern most of the chain． Gaotaishan used to be interpreted as a rhyolitic porphyry
based on the satellite image by Liu Jiaqi ( see part 8，chapter 2，Active Volcano in China ) ．
However，the in-situ field investigation by our study reveals that Gaotaishan has no volcanic
origin，but is in sedimentary rock with a bedding structure． All other hills with a “volcanic cone
appearance”are lithologically characterized by acidic igneous rock with phenocrysts as large as
2cm． There is no doubt that further work is needed regarding the volcanic source of the Binhu
volcanic chain．
1. 12
Sub -volcanic Cones and Chains
Besides the major volcanoes mentioned above，there are hundreds of sub-volcanic cones and
chains developed in the basin． These sub-volcanic cones are basically smaller in size ( about 10 ～
20m of diameters at cone base ) and lower in height ( from several meters to tens of meters ) ，
compared to the major volcanic cones． The formation of these sub-volcanic cones comes
predominantly from dark-colored splashdown deposits which are from the weak explosive
eruptions． The spatial distribution of these sub-volcanic cones is in a typically linear manner in
the northeast direction，which is a clear indication of regional tectonically controlled volcanism． It
is also worth noting that some of these cones have been cut off into small pieces，which reflects
the strong neotectonic activity after the intensive volcanic activity in the Ashikule basin．
2
PRELIMINARY CONCLUSION
The eruption mode of the Ashikule volcano group is various in different eruption episodes as
well as for different volcanoes． It can be summarized into two major modes，i． e． explosive
eruption during the formation of volcanic cones and subsequent lava overflow．
There is a close relationship between volcanic activity in the Ashikule basin and regional
tectonic activity． Specifically，the linear distribution of some volcanoes results from the effect of
regional fault activity，such as the NE-trending Altyn fault and ES-trending Kangxiwa fault．
Moreover，it has been observed that some original volcanic features have been altered by the later
neo-tectonic activity．
Based on the preliminary field survey of geological and geomorphological features of the
Ashikule volcano group，the volcanism process in the Ashikule basin can be divided into three
episodes． The first episode starts from the Pliocene epoch to early Pleistocene epoch，as in the
examples of the Xishan，Dongshan and Matishan volcanoes． The typical volcanic product in this
episode is represented by a strongly weathered lava terrace and volcanic cone remnant． The
second episode is in the middle Pleistocene，as represented by the Daheishan，Migongshan，
Yizishan，Maoniushan and Yueyashan volcanoes，which are characterized by broken volcanic
cones and moderately weathered lava flows． The third episode starts from the late Pleistocene to
Holocene，as represented by the Ashishan and Wulukeshan volcanoes，which are characterized by
well preserved volcanic cones and less weathered lava flows．
ACKNOWLEDGEMENTS
Fieldwork was supported by Prof． Xu Xiwei from Institute of Geology，China Earthquake
Administration，Profs． Song Heping and Shen Jun from Earthquake Administration of Xinjiang
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159
Uygur Autonomous Region，and Prof． Bai Zhida from China University of Geosciences ( Beijing) ．
This paper has been published in Chinese in the journal of Seismology and Geology，Volume
33，Number 3，2011．
REFERENCES
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the validity of “the eruption of No． 1 volcano in 1951”［J］． Acta Natural Resources，1989，4(4) :349 ～ 354
( in Chinese with English abstract)
Li Shuanke． Study on the geomorphology and Quaternary geology of the Ashikule basin，middle Kunlun Mountains
［J］． Acta Geographica Sinica，1991，46(2) : 224 ～ 232 ( in Chinese with English abstract) ．
Liu Jiaqi． Volcano in China ［M］． Beijing: Science Press，1999. 44 ～ 46 ( in Chinese) ．
Liu Jiaqi and Yiming Maimaiti． K-Ar age and distribution of Xikunlun Volcano in Quaternary ［J］． Science in
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Liu Ruoxin． Active Volcano in China ［M］． Beijing: Science Press，2000. 81 ～ 88 ( in Chinese) ．
Xinjiang Daily． Volcano Eruption Occurred in the Western Valley of Kunlun Mountains，Southern Xinjiang ［Z］．
May 7，1951，page 2 ( in Chinese) ．
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About the Author
Xu Jiandong，bron in 1962， is a research professor at the Institute of Geology， China
Earthquake Administration． He received his Ph． D． from the State University of New York Buffalo
in 1998． His curret research interests include volcanic geology and volcanic hazards． E-mail:
xujiandong@ ies． ac． cn